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A333742
Numbers k such that lambda(k) = lambda(k+2), where lambda is the Carmichael lambda function (A002322).
1
4, 6, 7, 180, 208, 427, 1183, 1330, 1404, 1480, 1584, 1651, 1672, 2013, 2695, 2715, 3256, 3439, 5250, 5668, 5698, 5950, 5955, 7600, 12243, 13392, 13715, 14768, 22263, 22878, 23347, 24804, 26100, 30500, 32940, 43648, 45870, 46205, 52548, 54481, 59148, 59780, 62719
OFFSET
1,1
LINKS
EXAMPLE
4 is a term since lambda(4) = lambda(6) = 2.
MATHEMATICA
Select[Range[10^4], CarmichaelLambda[#] == CarmichaelLambda[# + 2] &]
Position[Partition[CarmichaelLambda[Range[63000]], 3, 1], _?(#[[3]]==#[[1]]&), 1, Heads->False]//Flatten (* Harvey P. Dale, Aug 16 2024 *)
CROSSREFS
Sequence in context: A102133 A192121 A012760 * A107648 A004786 A263357
KEYWORD
nonn
AUTHOR
Amiram Eldar, Apr 03 2020
STATUS
approved